iio:ad5064: Initialize register cache correctly

Initialize the register cache to the proper mid-scale value based on the
resolution of the device.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/dac/ad5064.c b/drivers/iio/dac/ad5064.c
index f724a54bf334d7df536750b7497ff2c968cf7686..74f2d52795f6e6c44fe49025b49adbe13f33fc39 100644 (file)
--- a/drivers/iio/dac/ad5064.c
+++ b/drivers/iio/dac/ad5064.c
@@ -438,6 +438,7 @@ static int ad5064_probe(struct device *dev, enum ad5064_type type,
 {
        struct iio_dev *indio_dev;
        struct ad5064_state *st;
+       unsigned int midscale;
        unsigned int i;
        int ret;
 
@@ -474,11 +475,6 @@ static int ad5064_probe(struct device *dev, enum ad5064_type type,
                        goto error_free_reg;
        }
 
-       for (i = 0; i < st->chip_info->num_channels; ++i) {
-               st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
-               st->dac_cache[i] = 0x8000;
-       }
-
        indio_dev->dev.parent = dev;
        indio_dev->name = name;
        indio_dev->info = &ad5064_info;
@@ -486,6 +482,13 @@ static int ad5064_probe(struct device *dev, enum ad5064_type type,
        indio_dev->channels = st->chip_info->channels;
        indio_dev->num_channels = st->chip_info->num_channels;
 
+       midscale = (1 << indio_dev->channels[0].scan_type.realbits) /  2;
+
+       for (i = 0; i < st->chip_info->num_channels; ++i) {
+               st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
+               st->dac_cache[i] = midscale;
+       }
+
        ret = iio_device_register(indio_dev);
        if (ret)
                goto error_disable_reg;